1. FIELD OF THE INVENTION
This invention relates to a wall form structure and methods for their manufacture.
2. RELATED ART
There are many different ways to fabricate wall structures using such items as bricks, concrete blocks, or wooden frame construction. For example, cement blocks with hollow passages are often used to build walls. For many commercial applications, once the blocks are built up to a certain height, such as four feet, concrete is poured into the hollow passages in the blocks to strengthen the wall. Another four foot section is built on top of the first section, and so forth until the wall is completed. Reinforcing steel bars are usually placed within the open passages to reinforce the structure. Depending on the strength requirements for the wall, the poured concrete and steel rod reinforcement may not be needed. For example, the strength requirements for building a private house are generally less than those for commercial structures.
Constructing a wall from cement blocks as described above has several disadvantages. The process is time consuming because the many blocks used are each placed in proper alignment with those around it. In addition, it may be difficult to place wiring, plumbing, or insulation within the wall itself due to the structure of the blocks, which does not allow for easy access between the inner wall surface and the outer wall surface. Furthermore, the concrete region in a block wall may not be continuous, because it may be limited to the hollow passages within each block and the concrete regions in each passage may not contact the other concrete regions. The strengthening effect of the concrete is not as great as if one continuous concrete region existed within the wall.
A typical non-commercial structure wall may include a wooden frame, together with an inner wall surface of drywall board and an outer wall surface such as stucco. To build this type of wall, wooden studs such as 2".times.4".times.8" studs are placed every 16" or so along the desired wall area. To construct the outer wall surface, paper or wire mesh is tacked to the wooden studs and an outer wall surface material such as stucco is placed onto the paper or wire mesh. Drywall boards attached to the inside portion of the wooden beams form the inner wall surface.
This type of wooden frame wall has the advantage of allowing for relatively easy access to the region between the inner and outer wall surfaces for wiring, plumbing and insulation purposes. This type of wall construction has disadvantages. One major drawback is the time and labor necessary to fabricate the wall. Each wooden beam must be nailed into place, then the paper or wire mesh tacked on, the outer surface stucco applied, and the inner surface drywall attached to the studs. In addition, such a wall is not particularly strong, and cannot easily be reinforced with poured concrete and reinforcing rods.
One form of building wall using form construction is illustrated in U.S. Pat. No. 4,924,641 of Gibbar, Jr. Gibbar describes a composite wall fabricated of a combination of polymer forms which provide a latticework of voids into which concrete can be poured, providing a monolithic wall structure. One disadvantage of this structure is that wall boards, such as drywall or plywood, have to be secured to the finished composite wall structure to provide a finished interior or exterior wall. In addition, large interconnected voids are always formed between the walls, always requiring a large amount of concrete to be poured into the wall cavity.
U.S. Pat. No. 4,698,947 to McKay shows a wall structure including two foamed plastic sheets interconnected using a tie system. One disadvantage of this structure is a lack of compartmentalized cavities for containing the poured concrete. The McKay structure requires concrete to be poured within the whole wall structure to obtain any rigidity. Such construction techniques may require unnecessary amounts of concrete and may be less adaptable to different wiring, plumbing and insulation configurations.